DE60131565T2 - PLASMA REDUCTION PROCESSING OF MATERIALS - Google Patents

Description

FIELD OF THE INVENTION

The The present invention relates to the chemical processing of materials in a plasma environment and in particular it relates to pyrometallurgical Reduction processes in a plasma environment.

GENERAL PRIOR ART

The Pyrometallurgical reduction of metal-containing ores and concentrates usually involves heating of the ore or concentrate with a reducing agent in a melting furnace to a temperature at the usual the ore melts and during a chemical reaction of the ore / concentrate with the reducing agent, the ore / concentrate to a metallic product or to a higher value Reduced final product with a lower oxidation state. It be great Needed amounts of energy, to start and sustain the reduction processes in such furnaces to keep and the recovery rate of metallic products makes such processes commercial often not viable. The unreduced components of the ore / concentrate form one Slag that often contains a valuable metal content. The recovery of the metal content However, such slags is often again by conventional Process commercially unfeasible.

microwave irradiation is used in various industrial applications as an energy use Heating of metal has been used, including microwave heating from chemical precursors to kinetic and thermodynamic Stimulation of the same for the activation of chemical reactions. The treatment of metal-containing Ores and other comparable materials with microwaves been used as an intensive pre-processing, using energy applied to the ore to thermodynamically stimulate it and it for conventional recovery techniques such as conventional pyrometallurgical reduction, to prepare the leaching or hydrometallurgical recovery processes.

The publication DE Bullard's "Non-Equilibrium Plasma Processing of Ores", DC Lynch and WG Davenport, published in Thermal Plasma Applications in Materials and Metallurgical Processing, the Minerals, Metals and Materials Society, 1992 discloses the use of a microwave-induced plasma in the reduction processing of metal-containing ores. However, the process described requires an externally applied DC field for the reduction to take place. Further, the described process is performed at very low pressures between 0.4 and 36 Torr.

OBJECT OF THE INVENTION

It The object of the present invention is an improved pyrometallurgical To provide reduction process.

BRIEF SUMMARY OF THE INVENTION

In a broad aspect, the present invention provides a process for the reduction of a metal-bearing ore or concentrate comprising the steps of:
Preparing the ore or concentrate in a particulate form,
Charging a reaction chamber with the ore or concentrate, a reducing agent and an input gas,
Irradiating said reaction chamber with electromagnetic radiation within a frequency range of 30 MHz to 300 GHz until a plasma is excited in the non-equilibrium state, and
Maintaining and regulating said plasma in the nonequilibrium state with said radiation until said ore or concentrate is reduced to produce a reduction product.

Of the Pressure within said reaction chamber is during the Irradiation thereof above 40 kPa and below 300 kPa held.

The Contains reducing agent a carbonaceous material.

In some embodiments the pressure is about at atmospheric pressure held.

The Plasma can be excited in the input gas.

Optional or additionally at least a portion of the input gas may decay during irradiation, wherein the plasma is at least partially present in the decomposition product of the said input gas is excited.

The Reducing agent may be one mixed with the ore or concentrate particulate, contain carbonaceous material.

The Reducing agent may include carbon monoxide gas, with the input gas contains the carbon monoxide gas, wherein the plasma is at least partially excited in the carbon monoxide gas becomes.

The Reducing agent can be carbon monoxide gas and a particulate, carbonaceous Material included.

alternative For this purpose, the reducing agent may further contain a reactive metal.

The Input gas may contain an inert gas.

The Inert gas may include argon or nitrogen.

The Input gas may include air.

The Reducing agent may contain methane.

Preferably the radiation is microwave radiation.

The Ore or the concentrate can a concentrate derived directly from mined ore is.

Optional can the ore or concentrate is a concentrate that is not immediate derived from mined ore. Said non-ore concentrate may be derived derived, waste derived or mining derived concentrate, Such as from mine tailings or concentrator.

The Ore or concentrate can as a concentrate in the form of one of metallurgical machining processes derived residue be present such as a slag, a slurry or Sludge derived from metallurgical machining processes are. Such residues can pyrometallurgical, hydrometallurgical, chemometallurgical or electrometallurgical processing sections during the first, second and / or third stages of the metallurgical machining processes have been obtained.

The Reaction chamber may be in the form of a fluidized bed reactor available.

The Reaction chamber may optionally be in the form of an oven, wherein the ore or concentrate is loaded into a crucible which is placed in the oven.

The Reaction chamber may be in the form of a rotary kiln reactor.

The Reaction chamber may be in the form of a cyclone reactor.

The Reaction chamber may be in the form of a conveyor fed reactor.

In such a conveyor-fed Reactor, the ore or concentrate is preferably pelletized particulate Form prepared.

Preferably the reduction product is in metallic form.

The metallic reaction product may be in the form of vapor, wherein said vapor withdrawn from the reaction chamber and from the gases are separated during the said reduction be generated.

Optional For example, the reduction product is a compound in a reduced oxidation state.

The Reduction product may be by reduction of the ore or concentrate be formed by a series of subsequent reduction reactions.

The Method may include the step of generating carbon monoxide, wherein said plasma is at least partially in the carbon monoxide is stimulated and held.

If the input gas contains air and the reducing agent is particulate carbonaceous material contains can the carbon monoxide by the reaction of the oxygen in the air with the particulate, carbonaceous material are generated.

alternative or additionally can, if the input gas contains air and the reducing agent particulate, carbonic Contains material, the carbon monoxide by the reaction of the carbon dioxide, which while the reduction with the particulate, carbonaceous material is produced.

Otherwise, or additionally can the particulate, Carbonaceous material in the reaction chamber after stimulation be initiated by the plasma, wherein the carbon monoxide by the reaction of that during The reduction produced carbon dioxide and / or with the in the Air containing oxygen, if the input gas contains air, with the initiated particulate, carbonaceous material is generated.

Preferably becomes the ore or concentrate during the mentioned reduction and while of cooling of the reduction product after irradiation from said reaction chamber of enveloped in a non-oxidizing or inert gas environment.

Preferably is said non-oxidizing or inert gas during the cooling introduced into said reaction chamber.

In an embodiment the input gas is during the irradiation step passed through the ore or concentrate.

Preferably the input gas goes up blown through the ore or concentrate.

Preferably the input gas is preheated prior to loading into the reaction chamber.

It is a common one Conception that the production of plasmas during the chemical microwave processing of materials, and in particular while the pyrometallurgical reduction of metal-containing ores or Concentrates, harmful for the Process system hardware and diagnostic devices for monitoring and regulation and accordingly it is typical of such processes that they are controlled in a way that expressly the Avoid generation of plasma.

The Reaction speeds can but with one or more orders of magnitude in plasma processing increase. A plasma is a mixture of excited molecules, atoms, ions, Electrons and recombined particles in one at baseline host gas. With the high particle energies, which for such Characteristic components are different, the physical and pronounced chemical behavior of these component particles from the equivalent Particles "im Ground state ".

In pyrometallurgical processes, which are carried out in a plasma environment, There is a predominance of reaction chemistry at the plasma-solid interface or plasma fluid takes place. While this characteristic is characteristic of pyrometallurgical processes In general, the reaction rates are above this Border areas extraordinary by the plasma chemistry elevated, with a wealth on highly energized reactive species.

plasmas, the excited at "high" pressures and held to have an approximate equivalence the temperature between electrons and heavy particles (ions, Atoms, excited molecules) on. Accordingly, these plasmas are called equilibrium plasmas, here's one (approximately) thermal equilibrium exists between the particles. this shows especially at higher levels To press, because the high density of particles an increased frequency the collision between the particles provides, with the energy relatively uniform is distributed between the particles, giving a constant main temperature throughout in the particle species of the plasma. Due to the high energy densities (thermal mass), are equilibrium plasmas usually as a precursor process in materials processing because of their ability solid materials for heating, sintering, melting or to Evaporation has been used. These are all essentially physical Processes that merely have the advantage of physical thermal Perceive kinetics (properties) of the equilibrium plasma.

Non-equilibrium plasmas, which are more indicative of low pressure environments, are characterized by non-equivalency of particle temperature, with the "temperature" of the electrons far exceeding the temperatures of the heavier particles. 1 Illustratively illustrates the separation of the temperatures of the electrons and the heavier particles at low pressures, both with conventional plasmas and with plasmas stimulated by microwave (or RF) radiation. It can be seen here that at higher pressures the temperatures of the electrons and the heavier particles flow together. For a non-equilibrium plasma, the physical and chemical behaviors of the component particles may be substantially different than those in the equivalent ground state environment. For a non-equilibrium plasma with the different particle species moving at different energies, the measurement of such energy, typically measured in the form of a "temperature", will vary widely between species and between particles in each species population. This becomes apparent when the "temperature", a measure of thermal energy, is obtained by reading the average, taking out the electron voltages (temperature equivalents) of particles having no correction for the "thermal mass." Accordingly, the temperature of the plasma itself is meaningless, as particle "temperatures" may vary with four orders of magnitude and the "main" temperature measurements of the plasma differ by an order of magnitude by different methods.

The performance of processing non-equilibrium plasmas at low pressure is determined more by the reactivity of the existing chemically reactive species than by the total energy available in the plasma. This reactivity makes the non-equilibrium plasmas more suitable for systems that depend on the chemical kinetics of the chemical reactions, such as those of the present application, than the equilibrium plasmas, such as previously discussed, have been used primarily in physical processes.

The shape of the diagram in 1 will depend on several parameters, including the gas composition, the ionization properties of the species present and the form of energy applied to the system to produce the plasma. The pressure to which a plasma is in the nonequilibrium state will therefore vary depending on these and other parameters.

Typical processes for producing plasmas are by ionization by heating (thermal stimulation), ionization by irradiation and ionization by means of electrical discharge. While most plasma fabrication procedures will result in equilibrium plasma at pressures around atmospheric pressure, it is believed that the generation of plasma by irradiation, particularly in the ranges of RF and microwave frequencies between 30 MHz and 300 GHz, the curve of 1 As shown, to the right, plasmas will be displaced to produce plasmas in non-equilibrium and at operationally significant pressures around atmospheric pressure (101.4 kPa) and up to three atmospheres (about 300 kPa) with sufficient energy input, appropriate species present (chemistry) and can be maintained at reactive irradiation frequencies.

Here It is believed that this is the result of microwave irradiation which is the dielectrically different particles from the plasma Supplying energy, especially the electrons. At frequencies within the RF and Microwave frequencies can only the electrons in the ionized field follow the oscillations of follow the applied electric field. It follows that the electrons are so higher across from The heavier particles are energized by the plasma the RF / microwave plasmas are generally considered to be in non-equilibrium located plasmas can be defined. Such RF / microwave plasmas can over one huge Pressure range below 0.1 kPa (for processes outside of the Main interest of the present invention) up to pressures exceeding 300 kPa, to be stimulated and managed.

If a microwave field over A gas is applied to the charged particles in this gas accelerated. Because the mass of electrons is much, much smaller than which is the heavier ions, atomic and molecular particles, becomes the effect mainly from the field which are to give energy to the electrons. Accordingly, the Electron temperatures in the extremely high range of tens of thousands Degrees Kelvin lie while on the other hand, the apparent calorific mean temperature of the plasma (mainly determined by the heavier particles) is orders of magnitude lower.

The Reaction rates are generally controlled by mass transport diffusion by the dielectric heating mechanisms during RF / microwave processing very much increased is regulated by the starting materials, typically in the presence from an RF / microwave-stimulated plasma that, by definition, has a size Population of reactive species.

The Plasma processing using RF / microwave stimulation also allows one huge Degree of control over the process whereby the microwave irradiation on the filling of the starting materials can be aligned in such a way that the entire filling of the Starting materials within the reaction chamber is enveloped or discrete Zone within the filling is occupied. In continuous processing systems, the Residence time and the thermochemical parameters are effective through the Control of the applied radiation can be regulated, which is superior Provides machining or reduction results.

While lower pressures which is well below atmospheric pressure clearly, the generation of a nonequilibrium plasma with a great disproportion between the temperatures of the electrons and the heavier ones Ensure particles, if the pressure in the reaction chamber is too low, then the density of reactive species for performing the chemical processing for an economic one feasible Processing becomes too low. Accordingly, it is preferred that the pressure in the reaction chamber in which the plasma is excited and is held larger than 40 kPa.

Of the inherent advantage of non-equilibrium plasma chemistry (ionization chemistry) of nonequilibrium plasmas is when they are in chemical and metallurgical applications are used that these plasmas Can provide particles with the high energy needed to the chemical reactions at high kinetic speeds to stimulate and complete. For the Range of applications for the present invention relevant is, high rates of mass transfer are high kinetic Speeds desired. As a result, they are common commercially feasible productivity levels at the extremely low pressures, which provide extremely low rates of mass transfer, not achievable.

Vice versa there is the advantage of performing certain reactions under non-equilibrium plasma conditions, regardless of the low mass transfer rates, in that, the in the plasma environment of low density, the high-energy free Electrons and the ionized particles a greater free path on average return, before they experience a collision and recombination, which is an extraordinary increased energy for which confers recombination chemistry. These present at possible reaction sites allows increased energy, that the activation energy needs for the reactions that are extremely extraordinary high energy input for need their progress, is reached. As a result, can certain thermodynamically demanding metallurgical and chemical Reactions effective, if slow, or if at all, through the use of the extraordinary high-energy particles are carried out at low pressures.

processes, which need protection against reoxidation reactions benefit from the protection, as by removing potential sources of oxidation through initial and continuous removal of oxidizing reagents, such as for example, from the common reduction reaction product carbon dioxide, is included. This can be done by holding the process at low pressure and continuous evacuation of the reaction chamber can be achieved. Optional or additional can this carbon dioxide with fine carbon in the reaction chamber at elevated Temperatures are converted to the reducing agent carbon monoxide.

BRIEF DESCRIPTION OF THE DRAWINGS

The preferred forms of the present invention will now be further described by way of example with reference to the accompanying drawings, in which:

1 Fig. 3 is a diagram showing the separation of the temperatures of electrons and heavy particles at different pressures in a plasma.

2 Fig. 10 is a partial cross-sectional view of a reaction chamber used in the process of Example 1.

3 FIG. 12 is a partial cross-sectional view of a reaction chamber as used in the process of Example 2. FIG.

4 FIG. 12 is a partial cross-sectional view of a reaction chamber as used in the process of Example 3. FIG.

5 (a) Fig. 10 is a partial cross-sectional view of a reaction chamber used in the process of Example 4.

5 (b) an enlarged partial view of the upper portion of the reaction chamber of 5 (a) shows.

5 (c) FIG. 12 is a partial cross-sectional view of the gas generating system associated with the reaction chamber of FIG 5 (a) connected is.

5 (d) a cross-sectional view of the reaction chamber 5 (a) that was made at 5-5 cut.

6 Fig. 10 is a partial cross-sectional view of a reaction chamber used in the process of Example 5.

7 Fig. 10 is a partial cross-sectional view of a reaction chamber used in the process of Example 6.

8th Fig. 10 is a partial cross-sectional view of a reaction chamber used in the process of Example 7.

9 (a) Fig. 10 is a partial cross-sectional view of a reaction chamber used in the process of Example 8.

9 (b) a cross-sectional view of the reaction chamber 9 (a) which was made at section 9B-9B.

9 (c) a cross-sectional view of the reaction chamber 9 (a) which was made at section 9C-9C.

DETAILED DESCRIPTION THE PREFERRED EMBODIMENTS

EXAMPLE 1

This example describes in detail a process for reducing monazite [(Ce, La, Th) PO ₄ ] using a crucible batch reduction process to remove the phosphorus (from the phosphate) and the reduced heavy metals into a metallic or tungsten carbide Concentrate product. When the phosphorus is removed, the heavy metal (tungsten carbide) concentrate reaction product is suitable for further extractive workup in a route via halogenation, fractional distillation and then separation. The monazite used in this example contained La; Ce: Th in an approximate atomic ratio of 3: 1: 1. Other phosphate minerals are also similar to comparable phosphate minerals been processed. The device that was used to execute the process in this example is in 2 shown.

First became the monazite concentrate obtained from mineral sands by grinding to a particle size of less than 10 microns into a particular Form brought and intimately with a stoichiometric excess of 10% of a reducing agent in the form of fine pure carbon mixed. The fine mixture increases the available reaction area of the Boundary layer.

100 grams of the mixture of monazite and carbon were placed in a crucible 1 made of low-density alumina (see 2 ). The melting pot 1 formed of low-density alumina is permeable to microwaves. The monazite / carbon mixture became loose without compacting in the crucible 1 filled to maximize its permeability.

A microwave-permeable, aluminum silicate non-woven fabric covered as an insulating sheath 2 the exterior of the crucible, which was shielded to heat within the crucible 1 to keep. A partially open insulating hood 2a was placed over the opening of the crucible to isolate it while permitting the escape of gases and observing the crucible contents. The wrapped for isolation crucible 1 was subsequently placed in a reaction chamber 3 in the form of a dedicated, evacuatable reaction chamber capable of operating at an effective "full" vacuum of less than 0.1 kPa to 1000 kPa (about 10 atmospheres) 1 was placed on a microwave permeable spacer 4 made of refractory stone, so as to fill the monazite / carbon mixture towards the center of the reaction chamber 3 position in order to optimize its localization within the applied microwave field and thus simultaneously optimize the loading potential.

The reaction chamber 3 was then with a hood 5 locked. A sealing ring 6 with the addition of vacuum grease was used to make the connection between the upper protruding edge 7 the reaction chamber and the hood 5 to close. The protruding edge 7 and the hood 5 were then externally using a suitable clamp 8th stapled. The hood was covered with an observation port 20 to allow visual monitoring of the process.

The closed reaction chamber 3 was then passed over the reaction chamber outlet 9 evacuated using a suitable vacuum pump. The reaction chamber 3 was evacuated to the system pumping limit of less than 1 kPa, as on the vacuum gauge 10 controlled. The reaction chamber 3 was then passed over the gas inlet for two minutes with high purity argon gas 11 fed. The evacuation / charging cycle was then repeated three more times to ensure that substantially all of the air within the reaction chamber had been replaced by the argon gas. Removal of the air ensured that all of the oxygen had been removed from the reaction chamber leaving behind an inert atmosphere which protects the reaction product from reoxidation.

The argon feed was then turned off and the reaction chamber 3 evacuated to a minimum pressure of 40 kPa for the reduction process, the system pressure in turn via the vacuum indicator 10 was controlled for stability over a period of 5 minutes.

The reaction chamber was then irradiated with microwave radiation through a top-mounted waveguide 12 irradiated at a power of 1 kW and a frequency of 2,450 MHz. The waveguide 12 was made with a microwave permeable ceramic window 13 made of alumina at the interface to the reaction chamber 3 attached to close this and isolate it against the radiant heat.

The remainder of the argon gas (at 40 kPa) in the largely evacuated reaction chamber 3 was the ideal environment for the stimulation of a non-equilibrium plasma capable of initiating the initial solid-state reduction of the monazite using the carbon as the reducing agent, producing carbon monoxide (CO) as a by-product of this initial solid-state reduction. This initial solid-state reduction can be represented by Equation 1 (a) below: (Ce, La, Th) PO ₄ + 4C ⇒ (Ce, La, Th) OC + P + 3CO ⇑ 1 (a)

The CO produced in the above solid-state reduction itself becomes an effective reducing agent, transporting carbon in a gaseous form to the reaction interface with a greater efficiency. Also important for the kinetics of the reaction, it ionizes the gaseous CO in the microwave-stimulated environment to enrich the plasma and generate extremely active positive ion species (primarily CO ⁺ ) which are not present in the original argon plasma. While argon plasma has extremely high energy negative (including electrons), positive, recombined, and excited species, it does not provide reactive radical species. The ionization of the CO and the gas phase reduction of the monazite can be represented by the following equations 1 (b) and 1 (c): CO ⇒ CO ⁺ + e 1 (b) (Ce, La, Th) _PO4 + 3CO ⇒ (Ce, La, Th) OC + P + 3CO ⇑ ₂ 1 (c)

The CO in equation 1 (c) may be in the ionized form CO ⁺ .

Another final reduction step from the oxycarbide to a (complex) metal carbide was carried out again using CO (at least partially ionized) as the reducing agent. The following Equation 1 (d) can be used to adequately describe this last step of the reduction process: x (Ce, La, Th) OC + y CO ⇒ (Ce, La, Zh) _X C _Y + n CO ₂ ⇑ + m CO ⇑ 1 (d)

Again, the CO in equation 1 (d) may be in the ionized form CO ⁺ .

While these Reduction to the carbide was confirmed by the analysis showed the very hot carbide an inclination oxygen from the otherwise very stable oxide crucible (and other fire resistant Material with which it is in contact) and much of the carbide product material to the more stable oxycarbide phase (s) return.

During the above-mentioned reduction reactions, the gases produced thereby were discharged from the reaction chamber via the outlet 9 during the ongoing evacuation of the reaction chamber 3 aspirated and pumped so that the pressure in the reaction chamber always remained below 50 kPa (absolute). With this low pressure maintained throughout the process, the uninterrupted plasma can probably be assumed to have remained well within nonequilibrium conditions.

The microwave irradiation which sustains the plasma and the reduction reactions was continued until the characteristic CO plasma color could no longer be visually detected with the same intensity. This change in plasma color and intensity suggests that CO was no longer produced, indicating that the reduction has been completed, along with a concomitant reduction in pressure down to the pump limit. In this phase, the plasma is believed to have been primarily a CO plasma, with the argon predominantly during the constant evacuation through the reaction chamber outlet 9 was flushed through the system.

One minute above this visually determined point of diminished color and intensity of the CO plasma discussed above and about 10 minutes after the beginning of the plasma, the microwave energy was turned off. Argon was added to the still evacuated chamber via the gas inlet 11 and the pressure stabilized at 20 kPa (absolute) for one hour (mainly to include cooling by solidification). The vacuum pump was then decoupled and the reaction chamber 3 sealed at the pump side and refilled with high purity argon to a moderate positive pressure and held there until it was completely cooled before being opened the following day.

The reaction chamber 3 was slowly brought to atmospheric pressure, carefully opened so that the reaction product was neither disturbed, removed nor contaminated, and the crucible 1 from the reaction chamber 3 removed. The melting pot 1 contained the reduced heavy metal carbide (oxycarbide) product, with ash and gangue slag on top. The heavy metal content of crucible 1 was scraped from the crucible wall and stored as desired for analysis and further processing.

The metal reaction chamber wall 1 and the metallic solidification baffles 14 which the reaction chamber outlet 9 (which forms the vacuum pump inlet) by collecting the condensate from the hot vapor phases before exiting through the outlet 9 The recovered phosphorus was analyzed as a pure elemental phosphorus as expected by Equations 1 (a) to 1 (d) .The reactor components were subsequently prepared from the reaction products in preparation cleaned further batch processing.

EXAMPLE 2

This example describes in detail a process for economically recovering valuable metals from metallurgical wastes and slags using a crucible batch reduction process. The zinc was made from a zinc-containing slag by in situ reduction of the metal in the slag and recovery of the metal recovered as metallic smoke from the hot reaction layer. The zinc smoke may, at this time, be reoxidized to a refined grade of zinc oxide powder or reacted with a halogen to yield a zinc halide. In the context of this specification, it must be understood that a smoke includes a metallic vapor or a metallic oxide, metallic halide, or another similar vapor derived from a metallic vapor.

Of the Process was successful in a gas mixture of nitrogen and Carbon monoxide at atmospheric pressure carried out, in contrast to the reduced pressure in Example 1. Because metals how zinc is less of an "oxygen scavenger" than the "reactive metals" (such as La, Ce and Th from the reduced solid product phase of Example 1) showed the reduced zinc product of the present example a lower tendency for reoxidation and needed accordingly less protection against reoxidation. As a result, the process could successful at atmospheric pressure be performed, because of the tendency of the reduced product to reoxidize through the reduction conditions in the reaction environment from the reaction chamber repressed has been. The wished Smoke product (metal, oxide or halide) dictated the composition from and the related chemical possibilities for the Reaction chamber environment in which the zinc is reduced and smoked has been. In the present example, the effectiveness of the Process and product quality by creating and maintaining a nonequilibrium plasma at atmospheric pressure and accordingly were the difficulties and the effort for obtaining and controlling a reaction chamber environment avoided with reduced pressure.

The device that was used to execute the process in this example is in 3 shown.

The Zinc-containing metallurgical slag material, which is a mineralogical Content of zinc oxide (ZnO), or a more complex mineralogy with ZnO equivalents, became a particular Shape with a grain size of less ground to 500 microns and twice the stoichiometric Demand (with reference to ZnO) with a reducing agent in the form of fine reactive activated carbon mixed.

100 grams of the mixture was placed in an alumina crucible 101 filled. The filling was loosely packed to maximize the permeability thereof. The bottom of the crucible 101 was with fine passages 101 which pass through, whereby the soil becomes porous and allows the gases to rise through the loosely packed filling of slag and activated carbon. The crucible was placed on a stationary ceramic container 114 attached, which has an opening at the top, with the passages 101 from the crucible bottom is in communication.

The melting pot 101 and the container 114 were provided with an insulating sheath made of alumina silicate nonwoven fabric 102 isolated to the crucible 101 to shield against heat loss. The Isolated Crucible 101 and the container 104 were subsequently placed in a reaction chamber 103 placed in the form of a purpose-adapted commercially available 1,300 W microwave oven. The crucible / container assembly was placed on a suitable spacer 104 made of fire-resistant stone to the filling towards the center of the reaction chamber 3 to position and accordingly to place low within the applied microwave field. The openings of the crucible 101 were partially by a loose, microwave permeable insulating hood 102a covered to allow the escape of smoke reaction products, while most of the heat within the crucible 101 is held. An observation opening 120 in the lid of the reaction chamber 103 allowed the visual monitoring of the reaction process.

The reaction chamber 103 was closed and then simultaneously over the outlet 109 evacuated through a backing pump, while nitrogen gas into the reaction chamber 103 over the main gas inlet 111 flowed. After five minutes, the backing pump was disconnected and the nitrogen feed was used to rinse and fill the reaction chamber 103 increased to a positive pressure. The reaction chamber 103 was not inherently airtight and accordingly the pressure remained within the reaction chamber 103 near the atmospheric pressure. After being rinsed for five minutes, the main gas inlet became 111 closed. A reductant gas mixture of 20% CO in nitrogen was introduced into the vessel at a low flow rate 114 via a second gas inlet 115 passing through the bottom of the reaction chamber 103 associated with it. The supply of the reducing agent gas into the container 114 , at a positive pressure, resulted in the reducing agent gas passing through the passages 101 in the bottom of the crucible 101 flowed through and the slag / activated carbon filling penetrated.

The reaction chamber 103 was then using the microwave radiation at a frequency of 2,450 MHz and an applied power of 1,300 W over two opposite waveguides 112 coming from the reaction chamber 103 by microwave-permeable ceramic windows 113 sealed, irradiated. After several minutes of irradiation, with the slag / activated carbon charge and the gases within the reaction chamber being heated, a random thermal runaway in very different dielectrically arranged particles caused the generation of a CO / N ₂ plasma in and above the crucible 101 within the reaction chamber 103 out. This plasma could pass through the screened observation port 120 to be watched.

The interpretation of the plasma trap and the intensity of the radiant heat by the operator caused the microwave irradiation from the reaction chamber 103 with the applied power manually adjusted to provide adequate thermal consistency and overheating and failure from the crucible 101 to avoid by melting. From the previous experience and investigation and knowledge of the melting points of the present phases and the thermochemical reaction data, it was estimated that the process was carried out at "temperatures" corresponding to the range of 900 ° C to 950 ° C. As previously discussed, For example, the notion of temperature in a dynamic thermal system such as a non-equilibrium plasma is relatively meaningless, and accordingly, "temperature" measurements through a thermocouple or direct pyrometric line-of-sight techniques are impractical and almost meaningless information provide.

About one to two minutes after the excitation of the plasma, a metallic smoke rising from the plasma was already detected, indicating the reduction of the zinc oxide content of the slag. The solid and gaseous reduction state of the zinc oxide using the activated carbon and CO plasma as the reducing agent, respectively, can be represented by the following equations 2 (a) and 2 (b): ZnO + C ⇒ Zn + CO⇑ 2 (a) ZnO + CO ⇒ Zn + CO ₂ ⇑ 2 (b)

The CO in the equation 2 (b) may be in the ionized form CO ⁺ .

In particular, the metallic smoke is easily visually detectable, if it has been allowed to reoxidize, if it releases the reducing atmosphere from the crucible 101 leaves after it has separated from the slag by the reduction processes described in equations 2 (a) and 2 (b).

To produce a finely divided zinc oxide (ZnO) powder, an oxygen stream (O ₂ ) was introduced so that the reduced zinc metal vapor passes through the O ₂ stream, rapidly converting it to a fume from a solid zinc oxide phase which is light could be caught. While the passage of zinc metal vapor through the CO ₂ within the reaction chamber environment as a by-product of Equation 3 (b) also had the effect of oxidizing the zinc vapor, this reaction is less spontaneous and resulted in some zinc smoke that remained unconverted as a solid zinc fume. To produce zinc chloride (ZnCl ₂ ), Cl ₂ gas can be flowed across the hot zinc vapor. The zinc chloride produced had to be significantly cooled before a solid smoke product could be collected by precipitation on a cooled surface. The reoxidation processes can be represented by the following equations 2 (c) to 2 (e): 2Zn + O ₂ ⇒ 2ZnO ⇑ 2 (c) Zn + CO ₂ ⇒ZnO + CO ₂ ⇑ 2 (d) Zn + Cl ₂ ⇒ ZnCl ₂ ⇑ 2 (e)

The smoke product, depending on the system atmosphere in the form of metallic zinc, zinc oxide or a zinc halide, was passed through a microwave transparent borosilicate extractor 116 that's above the melting pot 101 was sucked by means of a suction fan via a vacuum-tight outlet valve to a precipitation and bagging system, where the smoke was collected as a solid fine ore.

As soon as smoking ceased to be visually imperceptible was the process as for finished and stopped the irradiation. The completeness the process became later by analyzing the slag material in the crucible remained, approved.

Immediately after the irradiation was stopped, the charge from the crucible was still reactive and at a high temperature for an extended period of time, and the flowing CO / N ₂ gas mixture was continued until the charge cooled to about 200 ° C would have. Continued inflow of nitrogen was then used to cool the system to ambient temperature.

EXAMPLE 3

This example describes in detail a process for reducing chromite (FeO.Cr ₂ O ₃ ) ore concentrate using a crucible batch reduction process resulting in a chromium-iron alloy. The device that was used to execute the process in this example is in 4 shown.

The process was carried out at atmospheric pressure, which had proved appropriate for this example. Further, instead of filling the reaction chamber with a gas mixture of nitrogen and carbon monoxide as in Example 2, air (composed mainly of N ₂ , O ₂ ) was used as the initial gas in the reaction chamber. The combustion of coal by heating and the micro-arc formation of the coal in the oxygen-rich environment for CO production were sufficient to protect the reaction product from reoxidation. Further, molten slag covers the reduced metallic product stages to provide further protection in this example, allowing the simpler and more economical processing variant with an atmospheric atmosphere at atmospheric pressure.

A high quality chromite ore concentrate was milled in a stoichiometric amount in a ring mill with a reductant in the form of brown activated carbon to a particle size of less than 200 microns. The mixture was loosely placed in a suitable microwave permeable oxide ceramic crucible 201 filled on top of a bed of granular activated carbon to unite the liquid metal products below the starting materials. Another layer of granular activated carbon was placed over the chromite / charcoal mixture fill to aid in protection against reoxidation. As in Examples 1 and 2, the crucible became 201 with an aluminum oxide silice fiber nonwoven existing insulating 202 and an insulating hood 202a isolated to limited observations through the observation port 220 and to allow the gaseous reaction products to escape.

The isolated crucible 201 was in the reaction chamber 203 in the form of a modified commercially available microwave oven, onto a ceramic block 204 which was "enriched" with air at atmospheric pressure, no rinsing or evacuation was performed.

The reaction chamber 203 was then run with 2,450 MHz microwave radiation at full furnace power of 1,300 W via top and side mounted waveguides 212 irradiated. The reaction filling in the crucible 201 heated rapidly due to micro-arcing between the carbon particles and then between the dielectrically-different particles in the charge mixture, resulting in some chemical reactions with low activation energy requirements. The release of energy from these initial exothermic reactions provided additional thermal energy to heat and activate the reduction reactions.

The initial micro-arc formation of the activated carbon in the applied microwave field in the oxygen-containing air environment produced CO according to Equation 3 (a) below, which provided protection against the reoxidation of the subsequent reaction products. 2C + O ₂ ⇒ 2CO ⇑ 3 (a)

As the temperature in the charge of starting materials increased, with massive deviations in local temperatures around an arbitrary temperature profile, a non-equilibrium nitrogen plasma in the mainly nitrogen-containing (air) atmosphere from the reaction chamber became 203 Subsequently, the heating in the filling of the starting materials is continuously uniform. With the highest temperatures established in and above the charge of the feedstock within the crucible, the plasma within the upper layers became the charge of the feedstock (by the plasma penetration from the static charge) and just above the charge of the feedstock within the crucible 201 , below the insulating hood 202a , concentrated. The radiation, and the plasma, penetrate deeper into the static crucible filling as the permeability of the filling increases.

Carbon monoxide (CO) activation stimulated by the nitrogen plasma, using activated carbon as the direct initial reducing agent, generates carbon monoxide (CO) as a byproduct of solid phase reduction, which ionizes and thus contributes to the plasma chemistry. The reactions produce a metallic chromium product leaving a Wustit (FeO) rich phase, which is reduced in a second stage. This result can be explained by the greater microwave sensitivity of Cr ₂ O ₃ to FeO (to heat up in a microwave field). The initial solid-state reduction of the chromite can be represented by Equation 3 (b) below: FeO.Cr ₂ O ₃ + 3C ⇒ 2Cr + FeO + 3CO ⇑ 3 (b)

That according to equations 3 (a) and 3 (b) is not thermodynamically stable below approximately 950 ° C when in an oxygen-containing environment, such as that present in the present example, and tends to cool with the oxygen present in the air atmosphere is to oxidize to carbon dioxide (CO ₂ ) according to Equation 3 (c) below: 2CO + O ₂ ⇒ 2CO ₂ ⇑ 3 (c)

However, with increasing temperature, in the plasma "temperature", the reverse case is generally correct, with free oxygen and carbon dioxide gas molecules in the atmosphere from the reaction chamber 203 immediately above the charge of the starting materials, whereby they are thermochemically predisposed to conversion (with charcoal) to carbon monoxide according to equations 3 (d) and 3 (e) below: O ₂ + 2C ⇒ 2CO ⇑ 3 (d) CO ₂ + C ⇒ 2CO ⇑ 3 (e)

The CO produced by these reactions ionizes even in the microwave-stimulated environment to enrich the predominant nitrogen plasma with high-energy, reducing CO ⁺ ions. In the reaction chamber environment, the plasma that envelops the charge of the reactants at the higher reducing "temperatures" is composed mainly of N ₂ and CO species, which protects the charge from possible oxidation reactions up to the endpoints of the plasma Ceiling of high energy reducing ions is maintained over the fill providing an extremely reducing environment Such protection is provided by the nature of the plasma and, in particular, non-equilibrium plasmas whose "chemical focus" is to analogize bonds in a manner to break down the chemical reduction reactions (that is, unlike chemical oxidation reactions where bonds are completed).

The change in the plasma chemistry with the generation of CO ⁺ ions could be visually observed as a shift in the characteristic emission color from the plasma and audibly detected by an associated shift in the power drawn on the magnetic field tubes when plasma excitation or Step increase is present.

The CO available in the ground, excitation, ionization and recombination states becomes an effective reducing agent which transports the carbon to the reaction interface with the chromite particles, which activates gaseous phase reduction from the chromite. At this stage, the reduction rates increase to a maximum. The ionization of the CO and the ionized gas phase reduction of the chromite can be represented by the following equations 3 (f) and 3 (g): CO ⇒ CO ⁺ + e ^- 3 (f) FeO.Cr ₂ O ₃ + 3CO ⁺ + 3e ^- ⇒ 2Cr + FeO + 3CO ₂ ⇑ 3 (g)

As previously discussed, the CO _{2 produced} at the higher plasma "temperatures" observed at this stage tends to CO (according to Equation 3 (e)). The subsequent solid and gas phase reduction from the Wustit (FeO) product Similar to equations 3 (b) and 3 (g) to metallic iron, it can be represented by equations 3 (h) and 3 (i) below: FeO + C ⇒ Fe + CO ⇑ 3 (h) FeO + CO ⁺ + e ^- ⇒ Fe + CO ₂ ⇑ 3 (i)

If desired, other initial reductant gases (typically CO) may be emptied into the reaction chamber prior to discharge 203 over the main gas inlet 211 introduced to support the various reduction processes. This will provide a reducing gas environment in the reaction chamber from the beginning rather than relying on the conversion of the O ₂ from the air to CO, as previously discussed.

The hot gases, including the reaction by-products CO and CO ₂ , plus minor gases or trace gases, dust and smoke were passed through a fume hood during the process 216 deducted, which is connected to an exhaust ventilation system.

During the reduction process, the metallic reduction product, which is in the liquid state as liquid metal beads, and when the individual beads increased in size and the surface tension was overcome, flowed as a liquid metallic phase to the bottom of the crucible 201 , being a pool 230 below a slag layer 231 was formed from gangue products, itself below the still-reacting bed filling the starting materials 232 formed until the decreasing solids from the bed 232 the filling of the starting materials in the liquid slag phase 231 into melted. At this time, the Mikrowellenbestrah set and the process ended.

The reaction chamber 203 was then allowed to cool together with the metal reaction product and the solidification of the slag phases allowed for mechanical recovery. Passive, slow cooling below the glowing activated carbon (to provide protection against oxidation) produced a "gray" iron alloy, while the alternative cooling process of cooling in water produced a "white" iron alloy.

In order to avoid oxidation of the metallic products during cooling, when the temperature within the crucible falls below the CO stability point of approximately 950 ° C, at which the CO would oxidize to the oxidizing gas CO ₂ , a non-oxidizing or inert gas into the reaction chamber through the main gas inlet 209 be taken in during cooling. Spectroscopic analyzes and metallographic analysis of the metallic reaction products identified a chromium-iron alloy with a typical composition of about 65% Cr (and up to 76% Cr in smaller iron spheres), less than 4% C and the difference in Cr Essentially Fe. The C uptake increased with prolonged time at elevated temperatures. The entire mineral matter was either converted to metal or slag leaving only activated carbon residues above the slag phase.

EXAMPLE 4

This example details a process for reducing cassiterite (SnO ₂ ) concentrate to extract metallic tin as a product. Instead of carrying out the reduction process in a solid crucible within a static vessel or a modified microwave oven as in Examples 1 to 3, in this example, the reduction process was carried out in a fluidized bed reactor using a carbon monoxide / nitrogen plasma. The configuration of the fluidized bed reactor is in the 5 (a) to 5 (d) pictured. The plasma reduction process can also be performed in other established and hybrid reaction chamber configurations using the same underlying process chemistry, including rotary kiln, cyclone, conveying runner, screw and gutter configurations.

Of the Process was high in the "atmospheres" pressure Bed up to higher Press under Pneumatic-like Conditions on the swirl plate (between 200 kPa and 300 kPa), where the initial Reduction workup via an applied microwave energy passing through the waveguide fed to the reactor bottom is carried out can be. The pressure drop through the fluidized bed is through the turbulence dynamics of the reaction chamber and different Parameters depends on the bed, which is itself swirling, including the bed height, the Particle density, particle shape and size range. A non-equilibrium plasma was along the full Height of the reaction chamber column with the support of additional Waveguides along the length held by the reaction chamber, wherein the application of the Mineral density, the susceptibility of filling for the Microwave irradiation and the applied power will depend. With the pressure drop through the fluidized bed, the nonequilibrium plasma became more stable Direction of the top of the reaction chamber.

The instantaneous example led the reduction work-up of a "low quality" cassiterite concentrate containing approximately 60% Sn. When using traditional reduction techniques for Sn, when using furnace crucibles, qualities below 65% Sn not wanted as it is economical not feasible is to process tin products that have a ratio of the "hardener" (iron / tin phase) to the recovered Have tin that is too high. When the iron is slightly reduced and the tin creates the iron / tin hardening phase, or Iron in the beginning Concentrate is high, are the traditional reduction techniques usually due to the overdrawn costs for extracting the tin from the iron / tin hardening phase commercial untenable.

The Ease of reduction of the cassiterite concentrates increases with increasing tin content from the low quality concentrates to the high concentrates Quality, being for the concentrates with higher quality was found to be more receptive are for Microwave irradiation as the lower quality concentrates.

The fluidized bed reactors are normally designed to perform continuous processing, but the present process was performed in a fluidized bed reactor configured and operated as a batch process reactor to allow closer control over the processing times of the cassiterite within the reaction chamber. Such close control is desirable when processing cassiterite to avoid over-processing of the cassiterite filling, which would be detrimental to later processing steps. However, if a smaller control for the reduction load by the applied electromagnetic Irradiation is required, the continuous fluidized bed process is preferred.

When the plasma process of the present example is used in either batch or continuous fluidized bed systems, the simultaneous reduction of gangue materials within the ore, particularly ferrous minerals, is avoided. As a result, this avoids the formation of contaminating phases (especially hardener, FeSn ₂ ) within the reduction product and the associated restrictive cost disadvantages of reprocessing such by-products in subsequent processes.

The fluidized bed reactor 300 in the 5 (a) to 5 (d) used in the present machining process comprises a stretched reaction chamber 301 , which is made of a high temperature resistant, corrosion resistant steel alloy. The reaction chamber 301 comes with a suitable fire-resistant insulation 302 isolated to keep the heat within the reaction chamber. An air gap may be between the outer wall of the reaction chamber 301 and the insulating sleeve 302 be shaped to block vibrations and to provide space for expansion.

A feed opening 303 for filling the starting materials is on top of the reaction chamber 301 for charging the reaction chamber 301 provided with the particulate filling of the starting materials. With reference to 5 (b) is a fold-out, self-sealing filling bell 304 inside the feed opening 303 set up for filling the starting materials. The filling bell 304 is rotatable and with spiral vanes 305 equipped, which in the distribution of the filling within the reaction chamber 301 participate. Other forms of apparatus for feeding reaction chambers, such as a rotary chute, may be optionally employed.

A perforated swirl plate 306 is at the bottom of the reaction chamber 301 localized. A vortex air box 307 is underneath and opens onto the swirl plate 306 , The vortex air box 307 is associated with a gas regeneration system (described below and incorporated herein by reference) 5 (c) pictured) that the gas is upward in the direction of the swirl air box 307 supplies. The composition and pressure of the pressurized gas, the vortex air box 307 supplied by a monitoring system 308 controlled.

An exhaust outlet 309 is adjacent to the feed opening 303 for the filling on top of the reaction chamber 301 localized. The exhaust outlet 309 feeds a smoke / solid product extraction system (not shown) to separate the smoke and solid fines of the products from the exhaust gases. This system then feeds the cooled, depleted gases into the chamber 310 from the gas regeneration system (see 5 (c) ) via a recycling outlet 311 back. The chamber 310 also has a fresh gas inlet 312 for introducing gases from outside the regeneration system and a pressure relief valve and outlet 313 for the escape of gases under excessive pressure.

A drain sheet 314 stands with the reaction chamber 301 immediately above the swirl plate 306 for purging the batch process fills after finishing processing of each batch in connection. The drainboard 314 is closed during processing and stands with a quenching chamber 315 for cooling / extinguishing derived material in connection.

Ceiling and ground waveguide 316 . 318 are at the top of the reaction chamber 301 adjacent to the feed opening 303 for the filling, or at the bottom of the reaction chamber in the vicinity of the swirl plate 306 localized. The upper waveguide 316 is positioned so as to irradiate the upper portion of the reaction chamber where the exhaust gasses formed by the reactions in the reaction chamber will be present. The bottom waveguide 318 is positioned so that it covers the bottom area of the reaction chamber above the swirl plate 306 irradiated. This is the area where the pressure in the reaction chamber will be highest. More additional waveguides 317 are on the periphery of the reaction chamber 301 localized, distributed between the ceiling and the floor and around the perimeter (see 5 (d) ). The number, frequency of irradiation and location of the waveguides will depend on the specific application and, in particular, will depend on the configuration of the reaction chamber and the properties of the fill to be processed. A microwave radiation at 2,450 MHz and a total variable power of up to 100 W per output were used in the present example. The general situation and orientation of the additional waveguides 317 , in the 5 (d) are depicted for multiple waveguides running along the reaction chamber 301 are positioned, preferably. Instead of supplying the radiation using waveguides, coaxial cables or any other suitable delivery means could be used.

In the process of the present example, first the cassiterite concentrate in parti in a granular size of less than 500 microns and in batches of closely spaced sizes (+/- 5% in grain diameter), which are then used to charge the reaction chamber 301 preheated to 200 ° C.

Preheated air was then over the air box 307 through the swirl plate 306 in the closed reaction chamber 301 initiated and through the exhaust outlet 309 out again. Once the reaction chamber had properly reached approximately 250 ° C, the preheated compressed air was replaced with a N ₂ / CO mixture (at an N ₂ : CO ratio of approximately 4: 1) preheated to approximately 300 ° C into the system via the fresh gas inlet 312 from the gas regeneration system. The CO gas was added to form the ionizing reducing agent for the reduction of the cassiterite.

While the reaction chamber 301 was rinsed with the N ₂ / CO mixture, the preheated Cassi terit concentrate was in the reaction chamber 301 through the feed opening 303 filled the filling until a complete filling has been achieved and to ensure that during the filling of the blower pressure of the N ₂ / CO mixture was adjusted so that the incoming filler did not pass the swirl plate and that the fine filler with the exhaust gases not was blown out of the reaction chamber. During filling the filling bell became 304 adjusted so that it regulates and distributes the charge of the starting materials and, in combination with the regulation of the N ₂ / CO blower pressure, through the swirl plate up into the reaction chamber 301 whereby the turbulence of the filling was created and maintained, the fine filling being in a fluidized suspension or "fluidized bed" 320 was held. This fluidized bed of feedstock particles maximizes the reaction interfaces between the cassiterite fill and the gaseous CO-reducing agent.

This swirling regime was established so that the fluidized bed was sufficiently stable and dielectrically incoherent to permit penetration of the microwave radiation from the various waveguides 316 . 317 . 318 to enable.

In order to establish and maintain such a swirl regime, which is stable and enables penetration of the radiation, the swirling gas flow through the swirl plate should be established 306 at the bed base with a pressure such that the gas, while carrying the bed of filling of the starting materials upwards and swirls, in the direction of the zone of lower pressure at the filling line of the bed (top surface of the bed in the direction of the lid from the reaction chamber) where the process pressure should be as low as or as close as possible to the atmospheric pressure (in the absence of a vacuum evacuation system) to thereby minimize the required swirling pressure. The pressure build-up between the swirl plate 306 and the fill line (which should be minimized) is determined by the swirling dynamics of the bed, and more particularly the particle size, density, size range, bed permeability and viscosities, and height of the bed. The swirl pressure at the swirl plate 306 is determined by providing the desired swirl regime while minimizing the top pressure at and above the fill line of the bed. This pressure on the swirl plate 306 is regulated by the pressure in the air box 307 is held. The pressure in the air box must be equal to the swirl pressure plus the pressure drop across the swirl plate 306 correspond and he was through the gas regeneration system 310 and the return control system 308 monitored and regulated.

Of the Process pressure range from which the swirl pressure at the swirl plate the highest should be kept below 300 kPa to the Plasma within the thermodynamic nonequilibrium regime to keep, with which the processing advantages of the extraordinary high-energy reactive particles is maximized, in particular of such particles, which have an immediate function in plasma reduction chemistry taking.

The reaction chamber was then irradiated with the microwave radiation at a frequency of 2,450 MHz via the waveguides and the power adjusted until a stable nitrogen / carbon monoxide non-equilibrium plasma was formed to the full charge level with predominantly reactive CO ⁺ ions. The common microwave frequency of 2450 MHz used for this and other examples described has been found to be extremely suitable for these applications and has therefore been used primarily for the sake of simplicity. Of other frequencies within the range of 30 MHz to 300 GHz, radio frequencies, although microwaves and having frequencies in the "millimeter wavelength", have been found to be equally well suited for the generation of nonequilibrium plasmas a decoupled range of susceptibilities to target minerals.

The swirling cassiterite was caused by the gaseous CO in various states (Ground state, excited and ionized) to form Sn and CO ₂ . The reduction in plasma phase can be represented by the following equation 4 (a) where * represents a non-ground state recombined particle or species: SnO ₂ + 2CO ⁺ + 2e ⇒ Sn + 2CO ₂ * 4 (a)

Once the plasma chemistry was stabilized, fine carbon became through the fresh gas inlet 312 to mix with the swirling pressurized gas (N ₂ / CO) such that the CO was regenerated by the CO ₂ generated during the reduction of cassiterite in the gaseous phase, thereby providing a continuous feed of CO ⁺ ions for the on-going Reduction of the cassiterite was ensured. This reaction, known as the Boudouard reaction, is represented by Equation 4 (b) below: C + CO ₂ * ⇒ 2CO 4 (b)

The Boudouard reaction is endothermic and accordingly it should only be used if the "temperature" moderation is adequate, and this reaction will only be effective at temperatures above about 940 ° C. Where, as a result of the above, the Boudouard reaction is unreasonable, CH ₄ can be used both as a reducing agent (both directly as methane or indirectly at temperatures above which methane to carbon and hydrogen decomposes), for the reduction of cassiterite and for the regeneration of CO for further reductions CH ₄ can be used both for regeneration of CO by reduction of _CO2 during the process and as a partial or complete replacement of CO in the initial input gas mixture as initial reductant for the reduction of the cassiterite. while CH ₄ itself not ionized , a dissociation (decay) at temperatures below 500 ° C in In the microwave field, before it reaches its ionization energy, the resulting hydrogen gas forms a plasma, as does the initial reduction product CO, once it is produced, thereby acting as a reducing agent for subsequent reduction in the plasma phase. Further, a fine carbon soot is formed as a by-product from the methane decomposition, which is ideal for the regeneration of CO. As a result, even if CO is not used as the initial input gas, it is soon formed as a reduction by-product and / or by the Boudouard reaction, degrading CO ₂ at high temperatures. The addition of methane to the fluidizing gas may also be used to replace the addition of solid carbon moieties to the fluidizing gas to allow the CO-regenerating Boudouard reaction 4 (b), as discussed above.

At the lower energy or "temperature" ranges of non-equilibrium plasmas, hydrogen is a less effective reductant than carbon or carbon monoxide, and the Boudouard reaction, which is endothermic, removes energy from the system when it delivers CO. Accordingly, it When CH _{4 is} selected as the initial input gas, a lower thermodynamic energy variant under its lower energy conditions, the "trace elements", such as Fe, Mn, W, and Si, possibly contained in the charge of the source of ore, are less likely to be present the same ease as cassiterite, yielding a purer reduction product.

In addition, the use of CH _{4 introduces} another gas into the system, resulting in a more complex mixture of exhaust gases requiring processing and separation. The chemical reactions associated with the introduction of CH ₄ can be represented by Equations 4 (c) to 4 (g) below, plus Boudouard Equation 4 (b): CH ₄ ⇒ C + 2H ₂ 4 (c) SnO ₂ + 2C ⇒ Sn + 2CO 4 (d) SnO ₂ + 2CO ⇒ Sn + 2CO ₂ 4 (e) 2H ₂ ⇒ 4H ⁺ + 4e ^- 4 (f) SnO ₂ + 4H ⁺ + 4e ^- ⇒Sn + 2H ₂ O 4 (g)

Additional chemical reactions that are significant with respect to the components of the gas mixture in the atmosphere of the reaction chamber (with the addition of methane) can be represented by Equations 4 (h) and 4 (i): 2CO + CH ₄ ⇒ 2C + 2H ₂ O 4 (h) N ₂ + CO ₂ + 2CH ₄ ⇒ 2C + 2NH ₃ + CO + H ₂ O 4 (i)

These reactions are also important for the regulation of the flue gases, the minimization of negative environmental influences and the recovery of process by-products as valuable materials. These reactions take place in the reaction chamber and, if desired, can be carried out in an intensive chamber from the exhaust outlet 309 completely finished. Since the stoichiometry is preserved, equations 4 (h) and 4 (i) have been generalized here in the form of the ground state for the sake of simplicity. Carbon monoxide and nitrogen will be ionized, while on the other hand (if not everything is already dissociated) methane breaks down into soot and hydrogen, which will ionize. Other reactions and results are possible, but less stable, and therefore unlikely.

During workup, exhaust gases are exhausted through the exhaust outlet 309 aspirated. The exhaust gas, when exhausted into a cyclone, can be separated to remove it and contain solid fines from the hot flue gases that are bound for gas scrubbing or recycling (regeneration).

The Reduction of the cassiterite produces tin (as in Equation 4 (a) indicated) in the form of liquid Microspheres which form within the cassiterite particles and on the particle surface, where by the inherent high surface tension of the liquid tin plus a film of material with higher Melting point by refusion or by-product of the reduction of gangue minerals.

At a processing point determined by the experience and an analyzed mean of the accumulated data (charge vs. time vs applied energy) with respect to the degree of reduction of all previous process batches, microwave irradiation from the reaction chamber becomes 301 completed. The particulate matter from the still-liquid bed is then cooled to about 200 ° C in a non-oxidizing pressurized gas (in this example nitrogen was used) to solidify the tin. The solids from the bed were then removed from the reaction chamber 301 through the drainboard 314 in the extinguishing chamber 315 drained for further oxygen-free extinguishment (if needed).

Of the Metallic tin content can then be removed from the quenched solids by a suitable electrochemical or other recovery process to be obtained. After the recovery from the highly pure tin, can be left behind, incompletely reduced Cassiterite or other particulate Mineral material dried and reworked by the Fluidized bed reactor returned to a subsequent filling mixture become. Any other fines derived from the tin recovery process can remain be subjected to further extraction processes to any remaining high quality Metal component (or toxic component, separation and Disposal required), the Metals such as Au, Ag, Th, rare earth metals (RE's), Ta, W or Bi include.

EXAMPLE 5

In the extractive reduction of comparable metal sulfides of the form MS ₂ , the "first" sulfur atom can be removed by reduction with relative ease to give the rough stone form MS Typically, in a second reduction step, more intense pyrometallurgical processes for removal of the remaining Sulfur is needed to make the primary metal.

This example describes in detail a process for the reduction of a solid state molybdenite (MoS ₂ ) ore concentrate yielding a crude molybdenum metal sponge - apparently "sintered" by lower melting point phases (gangue and impurity metals) was achieved in a continuous one-step process in which the pneumatics from a fluidized bed reactor with plug flow was used to attenuate and balance the applied electromagnetic energy and to uniformly stimulate reactions with a uniform distribution of energy through the descending column of filler Device that was used for the execution of the process is in 6 shown.

The used fluidized bed reactor with plug flow 400 has been configured for continuous editing. In such a reactor, the pressurized gas is from a pressure box 407 in the reaction chamber 401 through a perforated vortex ring 406 directed, which takes the place of the swirl plate of Example 3. Unlike the reactor configured for batch operation 300 in Example 3, the filling material of the starting material is interrupted or continuously over the filling bell 404 (or equivalent to the rotary chute) and swirled by the ascending compressed gas, the descending fluidized bed following the mechanics of the plug flow. The solids of the plug flow are completely reacted by the reactions of the process before leaving the reaction chamber 401 through the open drainage funnel 414 in the center of the swirl ring 406 in a quenching chamber 415 is passed through. The filling material of the starting materials is continuously in the reaction chamber 401 fed and the solids of the reaction products continuously without switching off the reactor removed.

In the present example, the molybdenite ore concentrate was prepared in a particulate form having a grain size of less than 200 micrometers and coated with a solid reducing agent in the form of granulated activated carbon in a size range range from 100 to 1200 microns with the stoichiometric ratio of 2: 1 C: S mixed. The selection of the granulated activated carbon in this higher size range is forcibly introduced to provide better permeability of the bed in view of the plate-like morphology of molybdenite. The filling with the molybdenite / activated carbon mixture was then prepared in preparation for loading from the reaction chamber 401 preheated to approximately 300 ° C.

At the beginning of the continuous process was preheated air through the reaction chamber 401 over the air box 407 and the swirl ring 406 properly in the reaction chamber 401 flushed in and through the exhaust outlet 409 out. When the temperature in the reaction chamber reached approximately 300 ° C, the preheated compressed air was replaced by a mixture of 10% CO in air previously preheated to approximately 300 ° C and at 600 ° C at the speed of 10 ° C per minute was increased.

While the reaction chamber was purged with the CO / air mixture at a low blower pressure such that the solid fines were not entrained and exhausted with the flue gases, the preheated filling of the molybdenite / activated carbon mixture into the reaction chamber 401 (at the calculated speed from the feed for the continuous process) via the feed port 403 for filling the starting materials and the filling bell 404 fed. An initial charge of the starting materials formed a temporary downcomer plug in the downcomer 414 between the closed drain control valve 419 and the first fill of material above the swirl ring 406 which was subject to complete processing once a continuous plug flow had been initiated. Once a continuous plug flow had been triggered, the drain control valve became 419 open. The first out-of-process, unprocessed and insufficiently processed material was removed from the quenching system and returned for mixing with fresh blend material. As the column reached full charge in the reaction chamber and during the startup stage, the new fluidized bed was monitored to establish and maintain the plug flow regime, indicating complete metallurgical conversion (after analysis) versus mean residence time (in the reaction chamber ) optimized. The fluidized bed regime has been established with sufficient fluidized bed stability and dielectric incoherence to allow the penetration of microwave radiation from the various waveguides 416 . 417 . 418 , the top, sides and bottom of the reaction chamber 401 in a manner similar to that provided in Example 3.

Of the Pressure at the top of the reaction chamber (pressure above the filling line of the bed) should be as close as possible in an atmosphere lie in the face of the pressure drop across the bed from the pressure at Soil that needed will keep the vortex regime), which makes it possible that the swirling pressure at the bottom of the reaction chamber below of the preferred limit of 300 kPa.

Although short electromagnetic wavelengths in regions above 12 GHz could have been preferred as a result of the increased sensitivity of molybdenite at these frequencies, as indicated by minerals sensitivity vs. silica analysis results. Irradiation frequency, irradiation was used (and deemed appropriate for this purpose) at the common frequency of 2450 MHz for reasons of availability and simplicity. Once the filling in the reaction chamber 401 stabilized near the fan temperature of approximately 600 ° C, the reaction chamber was irradiated with microwave radiation through the various waveguides 416 . 417 . 418 irradiated. The applied power was adjusted until a stable plasma with predominantly reactive CO ⁺ ions had formed in the nitrogen plasma. The CO ⁺ ions were formed following the conversion of O ₂ and CO ₂ in the presence of activated carbon as the temperature in the reaction chamber rises above 950 ° C, as discussed in the earlier examples, with the "temperature" of the reaction chamber to the ideal plasma reduction "temperature" of 1050 ° C to 1100 ° C (as measured by a shielded thermocouple).

While the exact reduction route that is achieved is not easy had the addition of small amounts of calcium oxide (CaO) to the filling mixture raw materials or pellets of dried pellets Molybdenite / calcium / brown Activated charcoal paste with a narrow size range, here 1.5 mm ± 0.1 mm to 3.0 mm ± 0.2 mm, which is ideal for the bed permeability and the reduction chemistries with enhanced kinetics were one promotional Effect on the reaction kinetics and the completeness the reaction.

Outstanding reduction reactions that are understood to occur during processing (without ionization equivalents) are presented in Equations 5 (a) through 5 (d): Equation 5 (a) gives the initial detachment from the first sulfur atom of MoS ₂ again and the subsequent reduction to the elemental molyb dan is represented by Equation 5 (b): MoS ₂ + O ₂ ⇒ MoS + SO ₂ 5 (a) 2MoS + C ⇒ Mo + CS ₂ 5 (b) CS ₂ + 2O ₂ ⇒ C + 2SO ₂ 5 (c)

Equations 5 (d) and 5 (e) represent the alternative route when calcium oxide has been added: MoS 2 + 2CaO ⇒ MoO 2 + 2CaS 5 (d) MoO 2 + 2C ⇒ Mo + 2CO 5 (e)

Once the plasma chemistry has stabilized, fine carbon can be fed to the fluidizing gas mixture such that, where needed, CO is regenerated from O ₂ and CO ₂ (generated during reduction) with the carbon high in the reaction chamber to produce the To provide protection from a reducing atmosphere in a similar manner as in Example 4. As discussed in relation to Example 4, the CO ₂ reduction, the Boudouard reaction, is endothermic and the equilibrium of the reactions in the reactor can be manipulated so that "temperature" profiles of the reactor can be maintained as the case may be in the earlier example.

Also, in a similar manner as in Example 4, CH _4, both to regenerate CO and to provide an extra control mechanism (in addition to the control of the applied electromagnetic radiation) by balancing the chemical energy generated by the exothermic reactions and that which has been absorbed by endothermic reactions within the reaction chamber. The various reactions resulting from the addition of CH ₄ are those of Equations 4 (c), 4 (b), 4 (f), 4 (h), and 4 (i) discussed in relation to Example 4 were. It should be noted that while the hydrogen increases its effectiveness as a reducing agent at the higher process temperatures of the present process, it does not tend to displace carbon monoxide in its reduction efficiency unless higher temperatures (above 2,000 ° C) are achieved. In addition, the dissociation of methane will result in the provision of active hydrogen in the production of hydrogen sulfide (H ₂ S) gas, which is usually a less desirable exhaust gas option. The additional reduction reactions resulting from the generation of hydrogen ions by the addition of methane can be represented by Equations 5 (f) and 5 (g): MoS ₂ + 2H ⁺ ⇒ MoS + H ₂ S 5 (f) MoS + 2H ⁺ ⇒ Mo + H ₂ S 5 (g)

At the bottom of the reaction chamber 401 The loose, liquid or particulate solid product from the descending bed was passed through the downcomer 414 drained. The rate of decrease in the bed was determined by the rate of drainage of processed solid material through the downcomer 414 which is controlled by the setting of the drain control valve 419 is controlled. The residence time in the reaction chamber is determined by the rate of decrease of the plug flow (of filling elements), which (provided unobstructed particulate fluidity) is controlled by the discharge rate, which in turn is regulated by the setting of the drain control valve. The residence time is determined by the parameters of thermochemical processing (such as chemical availability, contact and reaction interface diffusion, chemical species, available energy and energy required) and the physical and chemical kinetics which determine the overall rate of chemical conversion, hence also the time needed for the chemical transformation. The time required for the chemical transformation should ideally be slightly less than or equal to the intended residence time of the starting material in the reaction chamber.

The drained material entered the quench chamber 415 where it has been kept fluid during cooling to minimize particle agglomeration and to prevent bulk "sintering." The particulate solid product is in a form that can be easily steered and handled, and can be used for further refining processing. such as an arc or ion beam melt, are sent to a zone refining process.

As the product continuously from the fluidized bed reaction chamber (column) 401 was discharged, fresh material of the filling mixture was continuously filled to the filling line of the fluidized bed in a uniform manner so that the height of the filling line remained constant.

EXAMPLE 6

This example describes in detail a process for the reduction of hematite (Fe ₂ O ₃ ) using a conveyor to pass the charge material of the raw materials through a reaction chamber at atmospheric pressure in a continuous process. The device as a continuous conveyor fed reactor be that was used to run the process is in 7 shown.

fine hematite was treated with a reducing agent in the form of fine brown Activated carbon mixed and the mixture using a brown Aktivkohleaufschlämmung embedded in a paste, resulting in a Fe: C ratio of approximately 2: 3 resulted. The paste became pellets of approximately 3 mm diameter and agglomerated until hard.

The dried pellets 501 were then evenly over a sintered belt-like conveyor 502 configured so that it allowed the compressed gases to flow through it.

The pellets 501 on the conveyor 502 were subsequently passed through the reaction chamber 503 transported from the continuous conveyor fed reactor. The reaction chamber 503 is with an intake throttle area 503a with limited cross-section, an open main chamber area 503b and an outlet throttle area 503c configured with limited cross section.

The dried pellets 501 were first using microwave radiation via a waveguide 504 in the intake throttle area 503a irradiated at a frequency of approximately 915 MHz, thus providing a temporary heating of the pellets. This preliminary heating can bring the hematite / charcoal feeds above 500 ° C, near a temperature capable of initiating the initial reduction reactions. By removing the pellets from the area of the intake throttle 503a in the direction of the open main area 503b from the reaction chamber 503 They are transported by microwave radiation from the central waveguides 505 irradiated at a frequency of 2,450 MHz. In this central area, a hot airflow (at about 800 ° C) is applied to the pelletized feedstock charge from a blower inlet 506 mediated, immediately below the conveyor 502 in the center of the main chamber area 503b is positioned. The hot oxygen from the air flowing through the carbon from the (now glowing red) hot source materials from the conveyor charge (at temperatures up to 1000 ° C) rapidly converts the carbon to carbon monoxide. An N ₂ / CO plasma becomes immediately above the charge in the area from the blower inlet 506 maintained where it provides extremely high energy reactive species in the primary reduction zone.

The reduction of hematite to elemental iron occurs through a series of reduction reactions represented by the equations 6 (a) to 6 (g) below (without ionization equivalents), the general system pressure and the general system temperature and with respect to the local ionization environment from the plasma zone, the reaction path, which depends on the energy available for activation, and the reaction mechanism, whether solid-phase or gas-phase reaction, can be represented: 1.5Fe ₂ O ₃ + 0.5C ⇒ Fe ₃ O ₄ + 0.5CO 6 (a) Fe ₃ O ₄ + C ⇒ 3 FeO + CO 6 (b) FeO + C ⇒ Fe + CO 6 (c) 1.5Fe ₂ O ₃ + 0.5CO ⇒ Fe ₃ O ₄ + 0.5CO ₂ 6 (d) Fe ₃ O ₄ + CO ₃ FeO + CO ₂ 6 (e) FeO + CO ⇒ Fe + CO ₂ 6 (f) CO ₂ + C ⇒ 2CO 6 (g)

The exhaust gases produced by the reactions are exhausted through the exhaust outlet 507 extracted and treated for heat recovery or regeneration of the air flow.

The CO plasma becomes positionally in the center of the reaction chamber as a result of the location of the hot airflow inlet 506 and the positioning of the main waveguides 505 maintained the microwave irradiation upright. The sponge-like, solid reduced iron is subjected to cooling as it moves from the plasma zone toward the outlet restrictor region 503c emotional. When the iron cools below 950 ° C, nitrogen may leak into the atmosphere from the outlet throttle area 503c be initiated to the conveyor 502 to shield and protect the reduced iron prior to reoxidation, which could result from free _O2 or CO within the cooling chamber environment being converted to _CO2 at this lower temperature profile, wherein the CO ₂ has stability here.

EXAMPLE 7

This example describes in detail another process for reducing hematite to iron using a rotary kiln apparatus using the same basic preparation and chemistry as in Example 6. The device that was used for the execution of the process is in 8th shown.

Hematite / carbon pellets 601 prepared according to Example 6 were placed in a rotary kiln reaction chamber 603 via a Zuführungsöff voltage 602 the starting material filling fed. The reaction chamber 603 was over the gas inlet 606 loaded with a gas mixture of 10% CO in N ₂ at low speed while maintaining the pressure within the reaction chamber at about 1 atmosphere.

The 28-liter reaction chamber 603 was irradiated with microwave radiation at a power of approximately 1,000 watts and a frequency of 2,450 MHz via a waveguide 605 irradiated, which was positioned in a fixed end of the furnace, whereby a CO / N ₂ plasma throughout in the central (16 to 20 liters) core volume (not by the rotating filling nor by the helical ribs 609 occupied) of the rotating reaction chamber 603 was generated.

The microwave radiation was attenuated to prevent melting of the feedstock charge, detected and monitored by the inspection of the reduction product effluent discharged from the reaction chamber 603 over the drain outlet 608 was pulled. Both the solid and gaseous phase products of the reaction product were discharged from the effluent outlet 608 drawn.

EXAMPLE 8

This example describes in detail a process for reducing hematite (Fe ₂ O ₃ ) to a low carbon iron (Fe) product using essentially the technique of so-called solid phase reduction of aerial uptake ("solid state reduction technique of in-flight entrainment ") of fine particulate fill material into a cyclone reactor The apparatus used to carry out the process in this example is disclosed in U.S. Pat 9 (a) to 9 (c) shown.

First became hematite in a particulate Form by milling to a particle size of less than 20 microns prepared and intimately mixed with fine brown activated carbon, the to a grain size of less was ground as 100 microns.

The hematite / activated carbon precursor mixture was then passed through a cyclone inlet with a forced air stream preheated above 400 ° C 701 which is at the top of the cyclone reaction chamber 702 was localized, injected. The inlet 701 is tangent to the cylindrical upper wall portion of the reaction chamber 702 arranged such that the inlet-blower air and the injected filler of the starting materials a spiral way down through the reaction chamber 702 follows.

The forced air and the injected filling of the starting materials were irradiated with microwave radiation at a frequency of 2,450 MHz via a main waveguide 703 irradiated, which was arranged so that it irradiates the air and the starting material filling, as they pass along the inlet 701 prior to proper entry into the reaction chamber 702 get through. The power from the applied microwave radiation was regulated to raise the temperature of the blower air stream to 1000 ° C to ensure that free oxygen in the fine activated carbon pressurized gases from the injected charge mixture converts the O ₂ via carbon dioxide (CO ₂ ) to carbon monoxide (CO) converts. The pressure range from the process was kept below the preferred maximum pressure of 300 kPa so that the N ₂ / CO plasma that had formed beyond the port and in the cyclone reaction chamber was in the upper range of non-equilibrium conditions Air has been raised to an appropriate temperature to ensure that free oxygen (O ₂ ) and residual carbon dioxide (CO ₂ ) remaining in the forced air reacts with the fine activated carbon from the feedstock charge mixture to convert it to carbon monoxide (CO).

The starting material filling and the air also became further main microwave conductors 704 at the top of the reaction chamber 702 irradiated around the perimeter of the reaction chamber 702 were positioned as in 9 (b) displayed.

While the Frequency of 2,450 MHz used in the present example was found to be effective and efficient in the present example proved was for Frequencies above 12 GHz found that they are for this specific application are preferable.

In the environment of non-equilibrium N ₂ / CO plasma toward the top of the reaction chamber, the hematite was reduced to magnetite, Fe ₃ O ₄ , using the extremely high energy reactive CO ⁺ ions for the main reduction stimulation. The magnetite was subsequently reduced to the thermodynamically most stable iron oxide phase, Wustit, FeO, which was subsequently reduced to metallic iron. Any formation of a liquid phase by exothermic reactions was avoided by the "in-flight" cooling dynamics within the reaction chamber. The reduced product had more of the appearance of a solid phase reduction than that of a consolidation of a reduced liquid phase. Any tendency for CO ₂ production during the Sequence of reduction was blown in by Boudouard gasification between remaining Carbon and CO _{2 are} counteracted to CO (as in Equation 6 (g)) in the reaction chamber 702 to regenerate.

This CO regeneration process was completed by the addition of additional fine, free carbon through the cyclone inlet 701 supported. The CO produced by the CO ₂ can be used for further reduction in the various stages from hematite reduction to iron, and also provides protection against oxidation of the elemental iron product.

The reactions for generating and regenerating CO are endothermic, and accordingly, additional external energy was needed to maintain the temperature within the reaction chamber. This energy was provided by additional microwave conductors 705 delivered around the circumferential length of the reaction chamber 702 were positioned at regular intervals. A typical pattern of additional waveguides spaced at regular intervals around the circumference 705 is pictorial in 9 (c) shown. The additional waveguides 705 also provided the energy required for the last step of reduction of the FeO to metallic iron, which required considerably more energy than the initial stages of reduction.

The reduced iron particles cooled when the spiral path through the lower tapered region, below the action of the various waveguides, of the reaction chamber 702 came through, and as a result of the mass of iron particles, which were released from the entrained stream and into a collection chamber 706 at the bottom of the reaction chamber 702 fell. The collection chamber was filled with CO (or optionally inert gas) to protect the reduced iron from oxidation. The solid iron product coming from the collection chamber 706 was in the form of hard steel powder which had a relatively low carbon content (0.3 wt% to 1 wt% compared to iron).

The exhaust gases from the various reactions were via the exhaust outlet 707 which is in the center of the top of the reaction chamber 702 was positioned, sucked and discharged to the appropriate gas processing systems (dedusting, roughing, gas regeneration if applicable). The exhaust gases consisted mainly of N ₂ , CO and CO ₂ .

Of the Professional will recognize the way in which the various Forms of reaction using the stimulated by radiation Plasmas of the present invention can be applied.

KEY TO THE FIGURES

1

• EN:

  CONVENTIONAL PLASMA

  DE:

  CONVENTIONAL PLASMA

  EN:

  T _electrons

  DE:

  T _electrons

  EN:

  _Tions

  DE:

  T _ions

  EN:

  T _neutrals

  DE:

  T _{neutral particles}

  EN:

  MICROWAVE STIMULATED PLASMA

  DE:

  MICROWAVE stimulated PLASMA

  EN:

  PRESSURE (kPa)

  DE:

  PRESSURE (kPa)

Claims (36)

A method of reducing a metal-containing ore or concentrate, comprising the steps of: preparing said ore or concentrate into a particulate form; Charging a reaction chamber with said ore or concentrate, a reducing agent and an input gas; Irradiating said reaction chamber with electromagnetic radiation in a frequency range of 30 MHz to 300 GHz until a plasma is excited in the non-equilibrium state, and maintaining and regulating said plasma in the non-equilibrium state with said radiation until said ore or concentrate is reduced To produce reduction product; characterized in that: pressure in said reaction chamber during irradiation is maintained above 40 kPa and below 300 kPa; and said reducing agent contains a carbonaceous material. Method according to claim 1, characterized in that that said pressure is maintained at about atmospheric pressure. Method according to claim 1, characterized in that that said plasma is excited in said input gas. Method according to claim 1, characterized in that that at least part of said input gas during the decomposed radiation, wherein said plasma is at least partially in the decomposition product the said input gas is excited. A method according to claim 1, characterized in that said reducing agent is a par mixed with said ore or concentrate contains ticular carbonaceous material. Method according to claim 1, characterized in that that said reducing agent contains carbon monoxide gas, wherein said input gas containing said carbon monoxide gas, wherein said plasma at least partially in said carbon monoxide gas is stimulated. Method according to claim 1, characterized in that that said reducing agent is carbon monoxide gas and a particulate carbonaceous one Material includes. Method according to claim 1, characterized in that that said reducing agent further comprises a reactive metal. Method according to claim 1, characterized in that that said input gas contains an inert gas. Method according to claim 1, characterized in that that said inert gas comprises argon or nitrogen. Method according to claim 1, characterized in that that said input gas comprises air. Method according to claim 1, characterized in that that said reducing agent contains methane. Method according to claim 1, characterized in that that said radiation is microwave radiation. Method according to claim 1, characterized that said ore or concentrate directly from mined Ore is derived concentrate. Method according to claim 1, characterized that said ore or concentrate is not derived from ore Concentrate is. Method according to claim 1, characterized in that that said ore or concentrate is a concentrate in the form of a residue derived from metallurgical processing is. Method according to claim 1, characterized in that that said reaction chamber in the form of a fluidized bed reactor is. Method according to claim 1, characterized in that that said reaction chamber is in the form of a furnace, said ore or concentrate being incorporated in one of Oven placed crucible is loaded. Method according to claim 1, characterized in that that said reaction chamber in the form of a rotary kiln reactor is present. Method according to claim 1, characterized in that that said reaction chamber is in the form of a cyclone reactor. Method according to claim 1, characterized in that that said reaction chamber is in the form of a conveyor Reactor present. Method according to claim 21, characterized that said ore or concentrate becomes a pelletized particulate form is prepared. Method according to claim 1, characterized that said reduction product is of metallic form. Method according to claim 23, characterized that said metallic reaction product in the form of steam is present, said vapor from said reaction chamber subtracted and from during the said reduction produced gases is deposited. Method according to claim 1, characterized in that that said reduction product is a compound in a reduced amount Oxidation state is. Method according to claim 1, characterized in that that said reduction product by reduction of said Ores or concentrate through a series of subsequent reduction reactions is formed. Method according to claim 1, characterized in that that said method comprises the step of generating carbon monoxide wherein said plasma at least partially in said Carbon monoxide is excited and held. Method according to Claim 27, characterized that said input gas contains air, said reducing agent particulate contains carbonaceous material and said carbon monoxide by reaction of oxygen in said air with said particulate carbonaceous material is generated. A method according to claim 27, characterized in that said reducing agent contains particulate carbonaceous material and said carbon monoxide by the reaction of carbon dioxide generated during said reduction with said particulate carbon lenstoffhaltigen material is generated. A method according to claim 27, characterized in that the said particulate carbonaceous material in said reaction chamber after initiating the said plasma, the said Carbon monoxide by the reaction of during said reduction produced carbon dioxide with the said particulate carbonaceous introduced Material is generated. Method according to Claim 27, characterized that said input gas includes air and particulate carbonaceous Material in said reaction chamber after the excitation of said Plasma is initiated, said carbon monoxide by the reaction of oxygen in said air with said initiated particulate carbonaceous material is generated. Method according to claim 1, characterized in that that said ore or concentrate during said reduction and while of cooling said reduction product after the irradiation of said Reaction chamber is surrounded by a non-oxidizing or inert gas environment. Method according to claim 32, characterized in that that said non-oxidizing or inert gas during the cooling mentioned is introduced into said reaction chamber. Method according to claim 1, characterized in that that said input gas during the said irradiation step by said ore or concentrate is directed. A method according to claim 34, characterized that said input gas is upwardly through said ore or concentrate is blown. Method according to claim 1, characterized in that said input gas prior to loading in said reaction chamber is preheated.